Breathing is traditionally thought of as an automatic process driven by the brainstem—the part of the brain controlling such life-sustaining functions as heartbeat and sleeping patterns. But new and unique research, involving recordings made directly from within the brains of humans undergoing neurosurgery, shows that breathing can also change your brain.

Simply put, changes in breathing—for example, breathing at different paces or paying careful attention to the breaths—were shown to engage different parts of the brain.

“After drop” is common after swimming in cold water; you get out and feel fine, and then you start to get colder, sometimes growing faint, shivering violently and feeling unwell.

After drop happens because when you swim, your body shuts down circulation to your skin, pooling warm blood in your core. This process helps you stay in the water longer: with reduced circulation to your peripheries skin and sub-cutaneous fat is turned into a thermal layer, similar to a natural wetsuit – hence the wild swimmers’ term bioprene for fat.

I've recently decided that I'd like to continue swimming in the open water into the winter (not continually like Forrest Gump, 'cause that would be just too exhausting!), but even before I've even put a toe in the cold water, a good friend, who is always one to put the fear of God into you if she thinks you are being an idiot/stupid/risking life and limb, has already had her two penneth. She appears to be well versed to the dangers of cold water. Impressed, I enquire as to how she had become such an expert in the field. She admitted that she's quoting the RNLI's advice about the dangers of cold water to me having recently been on an educational visit and, well, (her words) "some of it had sunk in. I knew I'd need it one day to lecture my idiot friend who has no sense whatsoever! Why would you want to do it?"

If you're planning to swim through the winter then here's a few tips now that it's getting chillier ..........

Don't swim alone. swim with a buddy or at least have someone watching out for you from shore. Swimmimg with friends is safer than swimming alone if you watch out for each other and it's more fun and companionable than swimming alone.

Don't hang about chatting after your swim - that can wait. Get yourself dry, dressed and with a warm drink inside within 10 minutes as that's when the afterdrop will hit and the shivers will start.

Before you swim make sure your clothes are ready for when you get out. They should be right side out and stacked so that the clothes you want to put on first are on the top with your towel over them. When you're getting dressed sort out your top half first and then if you've got a robie or DryRobe put that on and sort out the bottom half.

You need cake, a flask, more warm clothes than you can imagine – and don’t even think about a hot shower.

All-year swimmers don’t wear wetsuits. That defeats the purpose.

You will never have enough warm clothes. You need many more things than you think you might need, to recover after a cold swim. Thermals, fleeces, your thickest jackets, woolly hats, gloves, socks and scarves. And you won’t want to take them off all day. It’s a pretty strong look.

I was meeting with 40 professional mariners last week to discuss their man-overboard procedures. Since they operated where the water is cold (under 60 degrees most of the year), I asked them my favorite question.

“If you go overboard in January wearing street clothes when the water is just above 33 degrees, how long until you become hypothermic?”

The other week, I found myself front crawling my way down the icy lane of Brockwell Lido at 8am.

It was a lovely sunny September morning but bloody hell, was it f*cking freezing.

Even wearing a wetsuit, I found myself gasping for panicky air, trying not to ice to death. I thought I was a pretty good swimmer until I found myself floundering in sub-zero temperatures barely able to go four lengths without wheezing like a 90-year-old.